TMeshSpatialSort | Unreal Engine 5.7 Documentation

Sorts a list meshes into a list of "Nests" where each Nest has an outer shell mesh and a list of contained-inside meshes

For example, if you have a "Russian nesting doll" arrangement of meshes [A,B,C,D] where A holds B holds C holds D:

If NestingMethod is InSmallestParent, the output will be: Nest 1: Outer: A, Inner: B, Parent: Invalid Nest 2: Outer; C, Inner: D, Parent: B Nest 1 conceptually corresponds to the outer and inner walls of the first doll, and Nest 2 the same of the second doll. (Note if the orientation-related booleans are set to true, this would only hold if the mesh orientations are also alternating)
If NestingMethod is InLargestParent, the output will be: Nest 1: Outer: A; Inner: B, C, D; Parent: Invalid In this case Nest 1 conceptually corresponds to there being a single outer structure, and the inner structure is left unsorted (Note for InLargestParent mode, you typically want bOnlyNestNegativeVolumes to be false)

For similar functionality in 2D, see the TPlanarComplex class


Name	TMeshSpatialSort
Type	class
Header File	/Engine/Source/Runtime/GeometryCore/Public/Spatial/MeshSpatialSort.h
Include Path	#include "Spatial/MeshSpatialSort.h"

Syntax

template<class TriangleMeshType>  
class TMeshSpatialSort

Name	Remarks	Include Path	Unreal Specifiers
TMeshSpatialSort ()		Spatial/MeshSpatialSort.h
TMeshSpatialSort ( TArrayView< const TriangleMeshType > InputMeshes, TArrayView< const FAxisAlignedBox3d > MeshBoundsIn )		Spatial/MeshSpatialSort.h

Name	Remarks
FMeshNesting	Outputs.

Name	Remarks
ENestingMethod

Name	Type	Remarks	Include Path
bOnlyCheckSingleVertexForNesting	bool	If true, we assume meshes don't intersect, so we can check if a whole mesh is inside another by testing a single vertex If false, we only consider a mesh inside another if every vertex of the smaller is inside the larger	Spatial/MeshSpatialSort.h
bOnlyNestNegativeVolumes	bool	If true, only negative-volume meshes can be nested (i.e., can be included in an FMeshNesting InnerIndices array)	Spatial/MeshSpatialSort.h
bOnlyParentPostiveVolumes	bool	If true, only positive-volume meshes can be assigned the "OuterIndex" of an FMeshNesting Leads to more logical nesting, but note: if true, a negative volume that isn't inside any positive volume mesh will not show up in any nests at all	Spatial/MeshSpatialSort.h
InputMeshes	TArrayView< const TriangleMeshType >	Meshes to be spatially sorted	Spatial/MeshSpatialSort.h
MeshBounds	TArray< FAxisAlignedBox3d >	Optional array of bounding boxes for each mesh	Spatial/MeshSpatialSort.h
NestingMethod	ENestingMethod	Which algorithm is used to determine nesting	Spatial/MeshSpatialSort.h
Nests	TArray< FMeshNesting >	Computed nests	Spatial/MeshSpatialSort.h
SkippedMeshIndices	TArray< int >	Indices of meshes that are not included in the "Nests" output, e.g. negative-volume meshes that are not inside any positive-volume mesh if bOnlyParentPostiveVolumes	Spatial/MeshSpatialSort.h

Name	Remarks	Include Path	Unreal Specifiers
void Compute()		Spatial/MeshSpatialSort.h